package t20211203;

/**
 * @Author: DengJia
 * @Date: 2021/12/3 21:54
 * @Description:
 */

public class Main {

}

interface A {
    CharSequence f();
}

interface B {
    String f();
}

class C {

}

class D extends C implements A, B {
//    @Override
//    public String f() {
//        return "";
//    }


    @Override
    public String f() {
        return null;
    }
}
